Because of graphene and phosphorene, two-dimensional （2D） layered materials of group IV and group V elements arouse great interest. However, group IV-V monolayers have not received due attention. In this work, three...Because of graphene and phosphorene, two-dimensional （2D） layered materials of group IV and group V elements arouse great interest. However, group IV-V monolayers have not received due attention. In this work, three types of SiP monolayers were computationally designed to explore their electronic structure and optical properties. Computations confirm the stability of these monolayers, which are all indirect-bandgap semiconductors with bandgaps in the range 1.38-2.21 eV. The bandgaps straddle the redox potentials of water at pH = 0, indicating the potential of the monolayers for use as water- splitting photocatalysts. The computed optical properties demonstrate that certain monolayers of SiP 2D materials axe absorbers of visible light and would serve as good candidates for optoelectronic devices.展开更多
Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7...Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.展开更多
基金This work was supported by the National Science Foundation of China （Grant No. 21503195）, Natural Science Foundation of Shanxi Province （2015021044）, and Open Research Fund of Key Laboratory of Advanced Energy Materials Chemistry （Ministry of Education）, Nankai University in China.
文摘Because of graphene and phosphorene, two-dimensional （2D） layered materials of group IV and group V elements arouse great interest. However, group IV-V monolayers have not received due attention. In this work, three types of SiP monolayers were computationally designed to explore their electronic structure and optical properties. Computations confirm the stability of these monolayers, which are all indirect-bandgap semiconductors with bandgaps in the range 1.38-2.21 eV. The bandgaps straddle the redox potentials of water at pH = 0, indicating the potential of the monolayers for use as water- splitting photocatalysts. The computed optical properties demonstrate that certain monolayers of SiP 2D materials axe absorbers of visible light and would serve as good candidates for optoelectronic devices.
文摘Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.
